/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.metadata.rescon;

import java.util.concurrent.atomic.AtomicLong;

public class SchemaStatisticsManager {

    private final AtomicLong totalSeriesNumber = new AtomicLong();

    private static class SchemaStatisticsHolder {

        private SchemaStatisticsHolder() {
            // allowed to do nothing
        }

        private static final SchemaStatisticsManager INSTANCE = new SchemaStatisticsManager();
    }

    /**
     * we should not use this function in other place, but only in IoTDB class
     */
    public static SchemaStatisticsManager getInstance() {
        return SchemaStatisticsHolder.INSTANCE;
    }

    public long getTotalSeriesNumber() {
        return totalSeriesNumber.get();
    }

    public void addTimeseries(int addedNum) {
        totalSeriesNumber.addAndGet(addedNum);
    }

    public void deleteTimeseries(int deletedNum) {
        totalSeriesNumber.addAndGet(-deletedNum);
    }

    public void clear() {
        this.totalSeriesNumber.getAndSet(0);
    }
}
